Contrary to the popular belief, America is not fat because of it's lack of movement. Although sedentary lifestyle contributes to the rising national obesity crisis, the major culprit is that people choose to eat food that is cheap and proceed to grub.

According to a new study published in the June edition of journal CA Cancer, the proliferation of cheap and affordable food is what makes people fatter.

The paper that sought to examine economic factors, lifestyle and health and its relation to obesity found, "Rising obesity rates coincided with increases in leisure time (rather than increased work hours), increased fruit and vegetable availability (rather than a decline in healthier foods), and increased exercise uptake. As a share of disposable income, Americans now have the cheapest food available in history, which fueled the obesity epidemic."

Obesity has increased rapidly over the past few decades. It has been believed that obesity reflects social disparities with weight gain more prevalent in certain race or ethnicity, education, geography or income.

The report also revealed weight gain was "similar across sociodemographic groups or geographic areas, rather than specific to some groups" with the highest body mass index (BMI) average within the groups with lower income and education and among some ethnic minorities.

While there are disparities in both health and weight between the different American groups, there is a trend of obesity across various groups. Everyone is getting bigger because food is generally cheaper. People spend less money on food by buying less nutritious food and thus buy more of it.

The study revealed since the 1930, Americans have lowered their spending on food from 25 percent of their disposable income to 10 percent today. Also, people aren't eating for high-calorie food, they're also selecting a more varied type of food.

According to CNN, Lead Authors Roland Sturm and An Ruopeng, "If you look at the data over time, you actually see a slight increase in exercise. And Americans have more access to fruits and vegetables," said Sturm who is associated with the RAND Corporation. "It's not Southern hospitality that is driving this trend, nor is it income or education. Really nothing protects us from this challenge of obesity."

The study recommends more research and identification of more effective strategies to find a sustainable, long-term solution to addressing the nation's health. Some suggestions included increasing access to physical activity, health awareness or following the strategy of South Africa in subsidizing healthier foods to promote better nutrition, as CNN reported.